By now the masses have virtually abandoned economists. Few any longer believe that practitioners of the dismal science, even equipped with today's advanced mathematical models and powerful computers, can calculate the prospects for unemployment or inflation #this year, let alone next. Economists have fallen in public estimation to the level of weather forecasters - both have been wrong just once too often.

If economists show little skill predicting events 12 months out, their luck in predicting long-term prospects - over decades, even centuries - hasn't fared much better. During the early 1800s, stockbroker-turned-economist David Ricardo propounded the dark view that scarce land and diminishing returns would inevitably undermine the future. More than a century later, John Maynard Keynes continued the doomsday march with his 1930 essay "Economic Possibilities for Our Grandchildren," which set out the thesis that wealth creation was bound to taper off. Market economies, thought Keynes, had seen their best days. The great man of 20th-century economics predicted that capitalism would slowly disappear, to be replaced by community and egalitarianism.

Tell that to Bill Gates.

But after a legacy of failure, an explanation of why economies expand and a set of coherent policies to promote growth may be at hand. And for that, the economics world can thank a rather unlikely hero, Paul Romer. The lively, bespectacled economist from the University of California at Berkeley is almost completely unknown outside the academic community. You won't find the 40-year-old self-proclaimed Deadhead sounding off about economic prospects on Sunday-morning news shows, or advising politicians - except his father, Roy, the Democratic governor of Colorado. Instead, the man superstar economist Paul Krugman says "busted the study of economic growth wide open" labors in near obscurity, shuttling between his office at Cal and another at Stanford's Hoover Institution.

There's an obvious explanation for Romer's lack of exposure: his work is highly theoretical, and his papers are peppered with dense algebraic equations and arguments that turn on something called the mathematics of convex sets. None of this detracts from the power of his central claim - that new ideas, embedded in technological change, drive economic growth and allow us to escape the gaunt future economists have so often imagined.

Call Romer an economist for the technological age. The world, in Romer's view, isn't defined by scarcity and limits on growth. Instead, it's a playground of nearly unbounded opportunity, where new ideas beget new products, new markets, and new possibilities to create wealth. "Old growth theory says we have to decide how to allocate scarce resources among alternative uses," says Romer. "New growth theory says, 'Bullshit!' We're in this world, it's got some objects, sure, but it's got these ideas, too, and all that stuff about scarcity and price systems is just wrong.'"

Romer burst onto the economics scene in 1986, with the first in a series of path-finding papers that revived the study of economic growth, which had been moribund for a generation. "Paul single-handedly turned it into a hot subject," says MIT economist and Nobel laureate Robert Solow. During the 1950s, economists, led by Solow, had fashioned some bare-bones models and concluded that technological change accounted for about 80 percent of economic growth. But they failed to specify what technology meant, and the model they devised gave no hint of how to figure it out or encourage its development.

This wasn't necessarily the result of stupidity. Economists in the postwar years "were mainly concerned about preventing another depression. That was on everyone's mind," says University of Chicago economist Robert Lucas, one of Romer's mentors. Economists pretty much aimed to prevent inflation and unemployment from running amok. But as the Great Depression receded into memory, economics students began to seek other challenges. And Romer, who studied physics in college but passed up law school to tackle economics, became captivated by the question of what drives economic growth.

It was a fertile field. For generations, mainstream economists had expected growth in the industrialized countries to taper off. Expecting diminishing returns - the idea that the punch provided by adding yet another farm, factory, or worker declines over time - economists, like cultists awaiting the apocalypse, had long looked to the day growth would end. But decade after decade, the economy defied their expectations. And by the time Romer arrived on the scene, new economies to the East, led by Japan, were exploding forth. Says Romer: "I looked at the problem and said, 'This theory doesn't have any clothes on,' and proceeded to start work on
it."

Kevin Kelly is a writer and former correspondent with Business Week, living in Oakland, California. He is not the executive editor of Wired. Kelly can be reached at (kev1438@aol.com)